Investigate the Duration of the Short-Term memory
Participants were shown non-sense Trigrams (3 letter words) and were asked to recall them after intervals of 3, 6, 9, 12, 15 or 18 seconds. Inbetween intervals the participant would be ask to count down in 3's from a given number- This is the interference task- it prevents rehersal.
After 3 seconds Participants could recall 80% of trigrams correctly. After 18 seconds only 10% of trigrams could be recalled correctly.
When rehersal is prevented, very little remains in the short term memory for more than 18 seconds.